Final answer:
In a colinear set of points with A in between C and N, the line formed by the three points is straight. The sum of AC and CN would be equal to AN, but AC + AN would not be equal to CN. CN is greater than AC.
Step-by-step explanation:
In a colinear set of points with A in between C and N, the line formed by the three points is straight. So, statement a is true.
The sum of AC and CN would be equal to AN, since all three points are on the same line. Therefore, statement b is true.
However, AC + AN would not be equal to CN, as AC + AN = AC + CN = AN, since all three points are collinear. Therefore, statement c is false.
Since AC is part of the line formed by the three points, CN must be greater than AC, so statement d is true.